121108coupling.jpgPark Slopers Maggie Gyllenhaal and Peter Sarsgaard, dubbed New York’s hippest stay-at-home parents by the Times, have joined the cast of Classic Stage Company's Uncle Vanya, to be directed by Austin Pendleton for a January opening. It's the second Chekhov play in a row for Sarsgaard, who's currently on Broadway in an excellent production of The Seagull, and the first time the couple have worked together, aside from a short film. In other stage news, Liza Minelli canceled last night's performance of her new one-woman Broadway show because she was "suffering from dehydration." Neil LaBute's reasons to be pretty will come to Broadway after all, but it's unclear whether Alison Pill will reprise her much buzzed-about role. And one performance of Will Ferrell's hotly anticipated Broadway show, You're Welcome America. A Final Night With George W Bush, will be simulcast on HBO.